My Doctor Mailed My CBC Results To Me - The

My doctor mailed my CBC results to me - the summary says that "lab results are within acceptable limits", but my Glomerular filtration rate is 73 when normal for my age is >90. It says I have Stage G2 (mildly reduced kidney function). My mother has polycystic kidneys - shouldn't I be concerned about this result? I am a white female, 53, excellent weight. I also have Sickle Cell Trait. Not sure if that can affect results. Thank you so much.